Structure for fixing heat exchanger in air-conditioner casing

ABSTRACT

A heat exchanger such as a heater is inserted into an air-conditioner casing and fixed thereto. Projected fixing members are formed at an opening of the casing through which the heater is inserted. The fixing member resiliently deforms to allow the insertion of the heat exchanger and automatically recovers its original shape to keep the heat exchanger at an inserted position. The fixing member may be formed in a hook shape having a sloped surface which is straightened when the heat exchanger is inserted and automatically recovers its original slope after the heat exchanger is fully inserted. Thus, the heat exchanger is easily inserted into the casing and firmly held therein without using parts for fixing the heat exchanger.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is based upon and claims benefit of priority of Japanese Patent Application No. 2002-180152 filed on Jun. 20, 2002, the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a structure for fixing a heat exchanger such as a heater in an air-conditioner casing.

[0004] 2. Description of Related Art

[0005] An example of a conventional structure for fixing a heater in an air-conditioner casing is shown in FIG. 7 attached hereto. After a heater 2 is inserted into an air-conditioner casing 4, hot water pipes 6 connected to the heater 2 are fixed to an air-conditioner casing 4 with clamps 7 and screws. In this manner, the heater 2 is prevented from being separated from the air-conditioner casing 4.

[0006] Since the clamps 7 and screws are necessary to fix the heater 2 in the air-conditioner casing 4, such additional parts have to be prepared and additional time is required for assembling the air-conditioner.

SUMMARY OF THE INVENTION

[0007] The present invention has been made in view of the above-mentioned problem, and an object of the present invention is to provide an improved structure for fixing a heat exchanger such as a heater in an air-conditioner casing. Another object of the present invention is to provide an air-conditioner for use in an automotive vehicle, in which a heat exchanger is mounted on and fixed in an air-conditioner casing by means of the improved fixing structure.

[0008] In an air-conditioner such as an automotive air-conditioner, a heat exchanger such as a heater is inserted into an air-conditioner casing and fixed thereto. To easily insert the heat exchanger into the casing and to fix the heat exchanger therein without using fixing components such as clamps and screws, projected fixing members that are resiliently deformable are formed at an opening of the casing through which the heat exchanger is inserted. The heat exchanger is inserted into the casing by resiliently deforming the fixing members and then fixed to a predetermined position by establishing an engagement between the fixing members and the heat exchanger. The fixing members resiliently recover their original shape after the heat exchanger is fully inserted into the casing, and thereby the fixing members automatically engage with the heat exchanger.

[0009] The air-conditioner casing may be made of a resin material, and the fixing members may be integrally formed with the casing. The fixing member may be formed in a shape of a hook that is resiliently deformable and having a sloped surface. The sloped surface is forcibly straightened by inserting the heat exchanger, and recovers its original slope after the heat exchanger is fully inserted into the casing, thereby fixing the heat exchanger to the predetermined position. Alternatively, the surface of the fixing member may be rounded so that it engages with a portion of the heat exchanger after the heat exchanger is fully inserted.

[0010] According to the present invention, the heat exchanger can be easily inserted into the air-conditioner casing and firmly held therein without using parts for fixing the heat exchanger.

[0011] Other objects and features of the present invention will become more readily apparent from a better understanding of the preferred embodiments described below with reference to the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a schematic view showing an air-conditioner mounted on an automotive vehicle;

[0013]FIG. 2 is a cross-sectional view showing the air-conditioner, taken along line II-II shown in FIG. 1;

[0014]FIG. 3 is a perspective view showing a heater inserted into an air-conditioner casing;

[0015] FIGS. 4A-4D sequentially show a process of inserting and fixing the heater in the air-conditioner casing, as a first embodiment of the present invention;

[0016] FIGS. 5A-5D sequentially show a process of inserting and fixing the heater in the air-conditioner casing, as a second embodiment of the present invention;

[0017] FIGS. 6A-6D sequentially show a process of inserting and fixing the heater in the air-conditioner casing, as a modified form of the second embodiment; and

[0018]FIG. 7 is a schematic view showing an example of a conventional structure for fixing a heater in an air-conditioner casing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] A first embodiment of the present invention will be described with reference to FIGS. 1-4D. As shown in FIG. 1, an air-conditioner is mounted on an automotive vehicle, so that heat exchangers are positioned substantially at a center portion of the vehicle. The present invention, however, is also applicable to other air-conditioners differently positioned. The air-conditioner includes an evaporator 1 for cooling, a heater 2 (a heat exchanger) for heating, a blower 3 for supplying air. The evaporator 1 and the heater 2 are disposed in an air-conditioner casing 4. The blower 3 includes a scroll casing 31 and a centrifugal fan 32 disposed in the scroll casing 31. An air stream generated by the centrifugal fan 32 is supplied into an air passage 40 formed in the air-conditioner casing 4.

[0020] The air-conditioner casing 4 is made of a resin material such as polypropylene. The heater 2 is composed of plural flat tubes through which engine coolant (hot water) flows, corrugated fines disposed between the tubes, and a pair of header tanks connected to both longitudinal ends of the tubes. The tubes and the corrugated fins constitute a heater core 2 a (refer to FIG. 4B). As shown in FIG. 3, a hot water inlet 2 b and a hot water outlet 2 c are connected to the heater 2. Hot water supplied to the heater 2 from the hot water inlet 2 b flows out through the hot water outlet 2 c.

[0021] Operation of the air-conditioner will be briefly described with reference to FIG. 2 which shows a cross-sectional view of the air-conditioner, taken along line II-II shown in FIG. 1. Air is selectively introduced into the scroll casing 31 from either the outside of the vehicle or a passenger compartment. The air stream generated by the centrifugal fan 32 flows through the air passage 40 and is first supplied to the evaporator 1 that cools the air. A portion of the air cooled by the evaporator 1 directly flows out of the air-conditioner casing 4. The other portion of the cooled air flows through the heater 2 that heats the air. An amount of air flowing through the heater 2 is controlled by adjusting an opening angle of an air-mixing door 41. Thus, temperature of air supplied to the passenger compartment is controlled. The conditioned air flowing out of the air-conditioner casing 4 is supplied to either a face portion of passengers through a face outlet 51 or a foot portion of passengers through a foot outlet (not shown), or to both the face portion and the foot portion. An amount of air flowing through the face outlet 51 is controlled by a face door 42. The conditioned air is also supplied to a windshield through a defroster outlet 52 when a defroster door 43 is opened.

[0022] Now, referring to FIGS. 4A-4D, a structure for fixing the heater 2 in the air-conditioner casing 4, as a first embodiment of the present invention, will be described. As shown in FIG. 4A, the air-conditioner casing 4 made of resin has an opening 44 through which the heater 2 is inserted. Resilient hooks 45 (projected fixing members) integrally formed with the air-conditioner casing 4 are positioned at an upper end of the opening 44. The resilient hook 5 has a sloped surface 45 a inclined toward the center of the opening 44. The heater 2 is inserted into the opening 44 in direction D shown in FIG. 4A.

[0023] As shown in FIG. 4B, the heater core 2 a of the heater is inserted into the air-conditioner casing 4 through the opening 44, pushing and deforming the resilient hooks 45. When the heater 2 is inserted into the air-conditioner casing 4 up to a position shown in FIG. 4C, the sloped surfaces 45 a of the resilient hooks 45 become parallel to the axial inserting direction D. The heater 2 is further inserted up to a position shown in FIG. 4D, where the resilient hooks 45 return to their original shape and engage with an upper end of the heater 2. At this position, a bottom end of the heater engages with a projected rib (not shown) formed on the air-conditioner casing 4. Thus, the heater 2 is held in and fixed to the air-conditioner casing 4.

[0024] Since the resilient hooks 45 having sloped surfaces 4 a are provided at the opening 44 of the air-conditioner casing 4, the heater 2 is easily inserted into the casing 4 by deforming the resilient hooks 45, and the heater 2 is fixedly held at its mounting position by the resilient hooks 45 returned to the original shape. Therefore, the heater 2 is fixed to the air-conditioner casing 4 without using such clamps and screws as in the conventional fixing structure. Accordingly, the number of parts required for fixing the heater 2 in the air-conditioner casing 4 can be reduced, and the process of assembling can be simplified. Since the resilient hooks 45 are integrally formed with the air-conditioner casing 4, no additional process is necessary to provide the resilient hooks 45. Further, since the resilient hook has the sloped surface 45 a inclined toward the inserting direction D, the resilient hook 45 is easily deformed when the heater 2 is inserted in the direction D. Since the resilient hook 45 recovers its original shape after the heater 2 is inserted up to the mounting position, the heater 2 is automatically held by the resilient hook 45.

[0025] A second embodiment of the present invention is shown in FIGS. 5A-5D. In this embodiment, projected fixing members 45 each having a round surface 45 b are formed in a vicinity of the opening 44 in place of the resilient hooks of the first embodiment. The projected fixing members 45 are formed on walls extending upwardly from an upper wall of the air-conditioner casing 4, so that the walls having the projected fixing members 45 are bent when the heater 2 is inserted into the opening, as shown in FIG. 5C. The projected fixing members 45 return to the original position after the heater 2 is fully inserted into the casing 4, as shown in FIG. 5D. Thus, the heater 2 is kept in the mounted position by the projected fixing members 45.

[0026] The second embodiment described above may be modified to a form shown in FIGS. 6A-6D. In this modified form, the projected fixing members 45 are formed on sidewalls in the air-conditioner casing 4, not on the walls outside the casing 4. When the projected fixing members 45 are pushed by the heater 2 in the insertion process, the projected fixing members 45 resiliently deform as shown in FIG. 6C, thereby allowing the heater 2 to go through the sidewalls. After the heater 2 is fully inserted into the air-conditioner casing 4, the projected fixing members 45 recover their original shape and engage with the upper end of the heater core 2 a, as shown in FIG. 6D. Thus, the heater 2 is fixedly kept at the mounted position.

[0027] The present invention is not limited to the embodiments described above, but it may be variously modified. For example, the resilient hooks or the projected fixing members 45 may be made separately from the air-conditioner casing 4, and the separately made fixing members may be connected to the casing 4. In this case, the fixing members may be made of a metallic material.

[0028] While the present invention has been shown and described with reference to the foregoing preferred embodiments, it will be apparent to those skilled in the art that changes in form and detail may be made therein without departing from the scope of the invention as defined in the appended claims. 

What is claimed is:
 1. A structure for fixing a heat exchanger in an air-conditioner casing, heat being exchanged between fluid flowing through the heat exchanger and air flowing through the air-conditioner casing, the fixing structure comprising a projected fixing member formed in a vicinity of an opening of the air-conditioner casing, through which the heat exchanger is inserted, the projected fixing member being resiliently deformed by pushing the heat exchanger against the projected member.
 2. The fixing structure as in claim 1, wherein: the projected fixing member is integrally formed with the air-conditioner casing made of resin.
 3. The fixing structure as in claim 1, wherein: the projected fixing member is a resilient hook having a sloped surface that provides a wider space at the opening so that the heat exchanger is smoothly inserted through the opening.
 4. The fixing structure as in claim 1, wherein: the projected fixing member has a round surface that engages with a portion of the heat exchanger to thereby fix the heat exchanger at a mounted position in the air-conditioner casing.
 5. The fixing structure as in claim 1, wherein: the heat exchanger includes a substantially hexahedron-shaped core; and an end portion of the core engages with the projected fixing member to keep the heat exchanger at a mounted position in the air-conditioner casing.
 6. An air-conditioner for use in an automotive vehicle, the air-conditioner including a heat exchanger fixed in an air-conditioner casing by means of the fixing structure defined in claim
 1. 